Intrauterine growth retardation (IUGR) in piglets is associated with a high rate of morbidity and mortality after birth due to gut dysfunction, and the underlying mechanisms remain poorly understood. This study selected six pairs of IUGR newborn male piglets and normal birth weight newborn piglets (Large White × Landrace) to investigate differences in intestinal structure and digestive functions, intestinal ERS and apoptosis, intestinal barrier function, and inflammatory response. The results showed that IUGR significantly reduced the jejunal villi height (p < 0.05) and the ratio of villus-height-to-crypt-depth (p = 0.05) in neonatal piglets. Additionally, the microvilli in the jejunum of IUGR neonatal piglets were shorter than those in normal-weight piglets, and swelling of the mitochondria and expansion of the endoplasmic reticulum were observed. IUGR also significantly reduced serum glucose and lactase levels (p < 0.05) while significantly increasing mRNA levels of jejunal IRE1α, EIF2α, CHOP, Bax, Caspase9, Mucin2, Claudin-1, Occludin, ZO-1, Bcl-2, IL-6, and IFN-γ (p < 0.05), as well as GRP78 protein levels in neonatal piglets (p < 0.05). These findings suggest that IUGR impairs intestinal structure and barrier function in newborn piglets by enhancing intestinal inflammatory responses, activating intestinal ERS and the signaling pathways related to the unfolded protein response, thereby inducing ERS-related apoptosis.

The gut microbiota plays an important role in host nutrient absorption, immune function, and behavioral patterns. Much research on the gut microbiota of wildlife has focused on feces samples, so the microbial composition along the gastrointestinal tract of wildlife is not well reported. To address this gap, we performed high-throughput sequencing of 16s rRNA genes and ITs rRNA genes in the gastrointestinal contents of a wild adult male Chinese muntjac (Muntiacus reevesi) to comparatively analyze the microbial diversity of different gastrointestinal regions. The results showed that the dominant bacterial phyla were Firmicutes (66.19%) and Bacteroidetes (22.7%), while the dominant fungal phyla were Ascomycetes (72.81%). The highest bacterial diversity was found in the stomach, and the highest fungal diversity was found in the cecum. The microbial communities of the large intestine and small intestine were of similar structures, which were distinct from that of the stomach. These results would facilitate the continued exploration of the microbial composition and functional diversity of the gastrointestinal tract of wild Chinese muntjacs and provide a scientific basis for microbial resource conservation of more wildlife.

The objective of this study was to examine the macronutrient content in the shoots, leaves, and culms of bamboo species across various seasons within the habitats of wild giant pandas and in the cultivated regions for captive giant pandas. Results showed that crude protein (CP), fat, ash, and primary moisture (PM) contents of bamboo shoots were elevated, while there was a reduction in fiber content when compared to the leaves and culms ( p < 0.05). Nutritional composition varied among bamboo sources, with wild bamboo leaves exhibiting higher CP concentrations and lower fiber content ( p < 0.05), and higher CP and lower fiber in the bamboo of Xiangling mountains were observed. Almost all species exhibited greater concentrations of CP and PM and lower level of ash in annual bamboo leaves compared to the biennial and perennial ( p < 0.05). Moreover, as the bamboo culms matured, there was an increase in acid detergent lignin (ADL), soluble sugar (SS), starch, and gross energy (GE) ( p < 0.05). The ash, fiber, and GE contents were increased while the CP and SS were decreased both in leaves and culms among different bamboo species from spring to summer and fall. Moreover, Fargesia displayed lower PM, fiber, and ash levels compared to other species studied, and especially over 20% CP concentration was found in the annual leaves of Bashania spanostachya . These results indicated that macronutrient values of bamboo leaves and culms varied among species and were significantly influenced by the age of growth and seasonal changes.

The ruminant gastrointestinal tract hosts a complex microbial ecosystem vital for nutrient absorption, with each segment displaying distinct morphological and microbial compositional features compared to monogastric animals. While most studies rely on fecal samples, these fail to capture region-specific variations, limiting insight into microbe–physiology adaptations. In this study, we investigated Elaphodus cephalophus by measuring circular, longitudinal, and mucosal layer thickness across intestinal segments and by profiling bacterial and fungal communities via 16S and its rRNA sequencing. The results found that the stomach had the thickest circular (484.2 μm) and longitudinal (385.2 μm) muscle layers among all gastrointestinal segments. The thickness of the circular and longitudinal muscle layers in the stomach and duodenum showed a highly consistent variation trend (r > 0.74). Bacterial diversity was highest in the stomach and lowest in the ileum; cecal and rectal communities were similar but distinct from those in the duodenum, ileum, and stomach. Firmicutes and Bacteroidota dominated the bacterial phyla. Fungal abundance and diversity peaked in the cecum and were lowest in the stomach; Ascomycota was overall dominant, whereas Basidiomycota was most abundant in the duodenum. This study provides baseline descriptive data on the gastrointestinal muscle layer morphology and gut microbiota of Elaphodus cephalophus, establishing a basis for further study.